JPH0841662A - Etching process display method - Google Patents

Abstract

PURPOSE:To provide an etching process display method which enables an operator to easily recognize the progressing condition of etching and to prevent operation errors of an operator in an etching process. CONSTITUTION:A prescribed initial value T is displayed by a freely increasable and decreasable scale display 11 displayed on an output display means 10 in a first step S1. The decreasing speed (s)of the scale display 11 corresponding to the etching rate of the film to be etched is calculated from the film thickness and etching rate of the film to be etched and the initial value T of the scale display 11 in a second step S2. The value (t) of the scale display 11 is successively decreased at the decreasing rate (s)from the initial value(t)simultaneously with starting of etching of the film to be etched in the third step S3. As a result, the film thickness of the film to be etched at every lapse time of etching is shown as the value(t)of the scale display 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an etching process display method, and more particularly to an etching process display method for displaying the progress of dry etching performed in a semiconductor device manufacturing process.

[0002]

2. Description of the Related Art In dry etching performed in a semiconductor device manufacturing process, it is necessary to grasp a real-time etching state in order to obtain process controllability. For example, in dry etching using a plasma process apparatus, a method of judging the progress of etching from the emission intensity of plasma is widely used. In this method, a plasma of a specific reaction product or an etching gas is detected from various plasmas existing in the process, and the detected intensity is monitored. Then, the progress of etching is indirectly observed from the change in the detected intensity.

[0003]

As described above, in order to grasp the progress of dry etching from the emission intensity of plasma, the progress of etching and the process of the change in emission intensity corresponding thereto are known in advance. Need to understand. However, the change in the emission intensity shows different processes depending on the film quality of the film to be etched, the structure of the wafer on which the film to be etched is formed, the gas species used for etching, and the like. Further, the software program for displaying the above-mentioned plasma emission intensity is often different for each device. These situations have exacerbated the man-machine interface between the dry etching equipment and the operator operating the equipment. And, it is a factor that induces a work mistake such as an operator missing the end point of etching.

Therefore, an object of the present invention is to provide an etching process display method that allows an operator to easily grasp the progress of etching, and to prevent the operator from making a mistake in the etching process.

[0005]

The etching process display method of the present invention for achieving the above object is performed in the following procedure. First, a predetermined initial value is displayed by a scale display that can be increased or decreased and displayed on the output display means. Next, the decrease rate of the scale display corresponding to the etching rate of the etching target film is calculated from the film thickness and etching rate of the etching target film and the initial value of the scale display. afterwards,
At the same time when the etching of the film to be etched is started,
The value of the scale display is decreased from the initial value at the decreasing speed.

[0006]

In the above-mentioned etching process display method, the value of the scale display is decreased from the initial value at the same time when the etching of the film to be etched is started. The rate of decrease is calculated from the film thickness and etching rate of the film to be etched and the initial value of the scale display in association with the etching rate of the film to be etched. From this, the value of the scale display shows the film thickness of the etching film corresponding to the progress of etching.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the etching process display method of the present invention will be described below with reference to the flow chart of FIG. Here, for example, an etching process display method for dry etching the silicon oxide film as a film to be etched when a contact hole is formed in a silicon oxide film formed on a silicon substrate will be described.

First of all, in the first step S1, an increase / decrease scale display is displayed on an output display means such as a computer display. Then, a predetermined initial value is displayed on this scale display. As shown in the correspondence diagram (1) of the first step S1, the scale display 11 displayed on the output display means 10 is displayed using dots arranged in the vertical direction on the screen of the output display means 10. It Then, a predetermined initial value T is displayed on the scale display 11. This initial value T is displayed using, for example, 100 dots.

Further, the output display means 10 displays a schematic sectional view 1a of the wafer. This sectional schematic diagram 1a
Is displayed by incorporating the scale display 11 displayed with the initial value T in the etching portion of the film to be etched. In the schematic cross-sectional view 1a, an etching film display 13 representing the silicon oxide is displayed on a base film display 12 representing the silicon substrate, and a mask display 14 having a hole pattern formed thereon is displayed. . For this reason, the scale display 11 is incorporated in the display portion of the etching target film display 13 where the mask display 14 is not displayed above.

Next, in the second step S2, from the initial film thickness x and the etching rate y of the film to be etched and the initial value T of the scale display 11, the decrease rate of the scale display 11 corresponding to the etching rate y is calculated. Calculate s. For example,
Initial film thickness x of etching film x = 1000 nm, etching rate y of etching film y = 500 nm / mim,
When the initial value T of the scale display 11 is 1000 = 1000 dots and the display cycle of the screen is 1/5 sec, the decreasing speed s = (T × y) / (12 × x) ≈4.2 dots / 5
sec. Here, the case where the etching gate y is shown as a function of time has been described. However, the etching rate y may be expressed as a function of the aspect ratio and the depth of the contact hole formed by etching.

Then, in the third step S3, the value of the scale display 11 of the output display means 10 is decreased at the same time when the dry etching of the film to be etched is started. Here, as shown in the correspondence diagram (2) of the third step S3,
The output display means 10 displays the scale display 11 at a value t which is reduced by 4.2 dots from the initial value T = 1000 dots each time the display cycle of the output display means 10 changes.

In the above etching process display method, the value of the scale display 11 is decreased from the initial value T at the same time when the etching of the film to be etched is started. The reduction rate s is calculated from the film thickness x and the etching rate y of the film to be etched and the initial value T of the scale display 11 in association with the etching rate y of the film to be etched.
From this, the value t of the scale display 11 indicates the film thickness of the etching film corresponding to the progress of etching.

Therefore, when the value (t) of the scale display (11) becomes 0 dots, the film to be etched 13 is to be etched.
It is a guide for the end point of the etching. Therefore, even when it is difficult to determine the end point detection such as the end point detection of etching by plasma emission, the scale display 1 as described above is displayed.
By incorporating 1 in the schematic sectional view 1a, the end point detection can be easily determined.

The above-mentioned etching process display method is performed by the output display means 10 incorporated in the system of the dry etching apparatus as shown in FIG. 2, for example. The system has the following configuration. The dry etching device 21 is provided with a plasma detection means 22, and the plasma detection means 22 is connected to a calculation means 23. Further, the calculation means 23 has an input means 24,
The operation unit of the dry etching device 21, the storage means 25 and the output display means 10 are connected.

The output display means 10 is the calculation means 2
First to third display units 10a-displaying the output from
It has 10c. The etching process shown in FIG. 1 is displayed on the first display portion 10a. The change over time of the plasma emission intensity is displayed on the second display portion 10b. Etching parameters are displayed on the third display portion 10c.

The calculating means 23 is based on the information on the etching inputted to the calculating means 23 from the input means 24, and the etching rate of the film to be etched stored in the storing means 25 and the cross section shown in FIG. The data for constructing the schematic diagram are extracted. Then, based on the extracted information and the input information, the decrease rate of the scale display is calculated, and the etching process is displayed on the first display unit 10a as shown in FIG. The second display unit 10 is also based on the detection intensity signal of the plasma emission input from the plasma detection unit 22.
The change in the plasma emission intensity over time is displayed in b. Further, the etching parameters are displayed on the third display unit 10c based on the information input from the input unit 24 to the calculation unit 23.

In addition to the display on the output display means 10 as described above, the calculation means 23 instructs the etching device 21 to start etching in accordance with the input from the input means 24.

The storage means 25 stores, for example,
The etching rate of each material to be etched is stored. This etching rate is stored for each material to be etched, etching conditions, processed shape by etching, and film quality of the etching mask. The storage means 25 also stores template data of each layer constituting the wafer in order to display the schematic sectional view 1a described in FIG. 1 on the first display unit 10a.

The above system operates as follows. First, the information on the film to be etched and the information on the etching are inputted from the input means 24. The information on the film to be etched is the film quality and film thickness of the film to be etched. The information about etching includes a processed shape formed by etching, film quality of an etching mask, etching conditions, and the like. When the above information is input from the input means 24, the arithmetic means 23 extracts data from the storage means 25 to output the first display portion 10 a of the output display means 10.
The cross-sectional schematic diagram 1a is displayed in FIG. A decrease rate of the value of the scale display is calculated from the data of the etching rate extracted together with this and the initial value of the scale display incorporated in the schematic sectional view 1a. Further, an etching parameter is displayed on the third display portion 10c.

After the above processing is completed, the start of etching is input from the input means 24. As a result, the calculation means 23 instructs the operation section of the etching apparatus 21 to start etching. At the same time, the first display unit 10a
The cross-sectional schematic diagram 1a of FIG. 1 is changed as shown in FIG. Further, the second display unit 10b displays a change with time of the emission intensity of plasma.

When the output display means for displaying the etching process is incorporated in the system of the etching apparatus as described above, the change in the schematic sectional view 1a described above and the end point of the etching which make it easy to visually recognize the progress of the etching. It is possible to observe the change in the plasma emission intensity for detecting P. Therefore, the end point of etching can be determined by using the change in the schematic sectional view as a guide.

In the above embodiment, the case where the film to be etched has one layer has been described. However, the present invention can also be applied to the case where the film to be etched has multiple layers. FIG. 3 shows, as another example, an etching process display method in the case of forming a wiring by etching a layer to be etched formed by stacking, for example, tungsten silicide and polysilicon.

In this case, as shown in FIG. 3 (1), the output display means 10 is a schematic cross-sectional view 3a in which scale displays 31a and 31b of upper and lower two layers are incorporated in accordance with the film to be etched.
Is displayed. The respective scale displays 31a and 31b are displayed with respective initial values Ta and Tb.

Further, in the schematic cross-sectional view 3a, a second underlayer indication 33 made of silicon oxide is displayed on a first underlayer indication 32 made of silicon, and a lower layer etching film indication 34 and an upper layer etching indication are formed on the upper layer. The film display 35 is displayed. In the upper layer of the upper etching film display 35,
An island pattern mask display 36 is displayed. For this reason, the scale displays 31b and 31a are arranged in the portion where the mask display 36 is not displayed above the display portion of the upper layer etching target film display 35. These scale displays 31a and 31b correspond to the scale displays 31a and 31b, respectively.
Are displayed in different colors so that they can be distinguished.

Then, similarly to the above-mentioned embodiment, the decreasing speeds of the scale displays 31a and 31b are calculated.

After that, as shown in FIG. 3B, the etching is started, and at the same time, the number of display dots is decreased from above the scale display 31a. Then, when the value of the scale display 31a becomes 0 with the progress of etching,
The number of display dots is reduced from above the scale display 31b.

In the above etching process display method,
The time when the value of the scale display 31a becomes 0 serves as a standard for the completion of etching of the upper etching target film, and the scale display 3
The time point when the value of 1b becomes 0 becomes a standard when the etching of the lower layer film to be etched is completed.

As described above, when the film to be etched is multi-layered, the change in the emission intensity of the plasma for detecting the etching end point becomes complicated and it becomes difficult to detect the end point. However, by observing together the information of the schematic sectional view described above, it is possible to visually predict the end of etching and easily detect the end point of etching.

[0029]

As described above, according to the etching process display method of the present invention, at the same time as the etching of the film to be etched is started, the value on the scale displayed on the output display means is used as the etching rate of the film to be etched. It becomes possible to show the film thickness of the film to be etched for each elapsed time of etching as the value of the above scale display by reducing the film at a predetermined rate corresponding to. Therefore, the value displayed on the scale serves as a guide for judging the progress of etching, and for example, the end point of etching by the end point detecting means can be easily judged. Therefore, it becomes possible to prevent the operator from making a mistake in the etching process.

[Brief description of drawings]

FIG. 1 is a flowchart and a corresponding diagram showing an embodiment.

FIG. 2 is a configuration diagram showing a system of an etching apparatus.

FIG. 3 is a diagram illustrating another embodiment.

[Explanation of symbols]

 10 Output display means 11, 31a, 31b Scale display T, Ta, Tb Initial value

Claims (1)

[Claims] 1. An etching process display method for displaying the progress of etching when etching a film to be etched, wherein a predetermined initial value is displayed on an adjustable scale display displayed on the output display means. A second step of calculating a reduction rate of the scale display corresponding to an etching rate of the etching target film from a film thickness and an etching rate of the etching target film and an initial value of the scale display; As soon as the film etching starts,
A third step of decreasing the value of the scale display from the initial value at the decreasing speed, the etching process display method.